Two-dimensional materials-based hybrid transparent conductive electrode application into functional devices including energy harvesting and microelectronics

Abstract

This doctoral thesis provides an in-depth examination of the utilization of two-dimensional (2D) materials in the development of hybrid transparent conducting electrodes (TCEs) for energy harvesting and microelectronics. Flexible TCEs play a crucial role in the functionality of flexible solar cells. Their performance, particularly in terms of light and charge transmission, is vital. Thus, choosing Flexible TCEs with optimal properties, specifically in terms of electrical conductivity, light transmission, and mechanical flexibility, is fundamental to the creation of high-performing solar cells. Emphasizing the importance of the cathode or anode in solar energy harvesters, the thesis discusses the limitations of traditional materials like indium tin oxide (ITO) and fluorine-doped tin oxide (FTO), and the potential of 2D materials like micro metal grid, graphene, and others in overcoming these challenges. Chapter 2: Graphene-Enhanced Transparent Conducting Electrodes This chapter discusses the crucial role of graphene-encapsulated copper grids in the realm of TCEs for organic solar cells. This innovative design not only boosts electrical conductivity but also serves as an oxidative barrier, thereby enhancing power conversion efficiency and resolving long-term stability challenges, thus pioneering future developments in metal grid-based optoelectronics. The chapter further explores the importance of flexibility and stability in perovskite solar cells (PSCs), addressing these challenges through the integration of a graphene capping layer. This approach effectively reduces metal-induced degradation and interlayer diffusion, enabling flexible PSCs to maintain performance on par with rigid counterparts and marking a significant step forward in the design of robust, flexible solar cells. Chapter 3: Graphene-Based Transfer Techniques toward Flexible Electronics In this chapter, the focus shifts to the transformative impact of graphene on the fabrication process of flexible electronics. By leveraging the unique anti-adhesion properties of graphene, an innovative 'peel-and-pick' transfer technique for metallic electrodes has been devised. This development leads to the creation of devices characterized by outstanding conductivity, durability, and versatility across different substrates, indicating a progression towards more efficient manufacturing methods for flexible electronic components. Chapter 4: Flexible and Self-Encapsulated Semitransparent Solar Cells This chapter delves into the significant advancements in semi-transparent perovskite solar cells (PSCs) achieved by incorporating a graphene electrode and employing a bifacial cation exchange technique. This approach results in a notable efficiency of 15.1%, coupled with enhanced operational stability and mechanical robustness, crucial for the evolution of building-integrated photovoltaics. The chapter concludes by showcasing a strategy to precisely control the nucleation and growth of perovskite films using a supersaturation-suppression layer, substantially improving efficiency and stability in PSCs. Chapter 5: Nucleation Dynamics and Defect Control for Efficient Perovskite Solar Cells Lastly, the thesis highlights a method to fine-tune the nucleation and growth of perovskite films via a supersaturation-suppression layer, significantly enhancing efficiency and stability in PSCs. This innovation leads to devices with an exceptional 23.4% efficiency and improved longevity, overcoming common limitations associated with perovskite crystallization and defect formation. Collectively, these studies embody the thesis' aim to enhance the functionality and application scope of TCEs, emphasizing the role of two-dimensional materials as key components in the next wave of energy-related devices and flexible electronic systems. The work presented lays down a foundation for TCEs that excel in performance, are cost-effective, and possess intrinsic stability—attributes critical for the technological evolution of solar cells and microelectronic devices.